I have a new Cobb Accessport coming for my 2010 E92. I have an emergency jump starter from Costco that is essentially a portable car battery that you connect to the terminals under the hood. I'm thinking of using this while I update the ECU with the Cobb for the first download ~20 minutes to make sure my battery doesn't run low.
Is there any problem in doing so, and can I leave the hood of the car up while Cobb is updating? Any problem with opening/closing the hood during update, or does it have to be left alone like the car door?